[mfateev]

Because it is a hard problem to solve holistically.

It looks simple on the surface. So almost any company ends up creating an implementation similar to the one described in the article. Then it learns that it is much harder than looks, but it is usually too late. So they end up maintaining it for a long time with the original team long gone.

BTW I believe that temporal.io (I'm tech lead of the project) is so far the best open source solution to this problem.